临南油田夏32断块沙二段下部储层特征及其主控因素

通过岩芯和薄片观察，结合测井资料，对临南油田夏32断块沙二段下部储层发育特征及其主控因素进行了研究。结果表明：该区储层的岩石类型主要为岩屑质长石砂岩和长石质岩屑砂岩，颗粒分选中等，磨圆较差，成分成熟度及结构成熟度中等；储层物性表现为中低孔特低—低渗的特征，且孔隙度和渗透率相关性较好；孔隙类型包括原生粒间孔、粒内溶孔、粒间溶孔和铸模孔。综合储层特征的研究结果认为：夏32断块沙二段下部储层主要受基准面旋回、沉积、成岩以及构造作用的影响；三角洲平原的分支河道砂体物性最好，其次是三角洲前缘的水下分支河道，其他沉积微相储层物性较差；压实作用和胶结作用破坏储层物性，溶蚀作用则可改善储层物性；此外，构造作用所产生的裂隙也有利于改善储层物性，对储层物性起到了积极的建设作用。

Reservoir characteristics of the lower part of the 2nd member of Shahejie Formation in Xia 32 block in Linnan oilfield and their main controlling factors

This work discussed the reservoir characteristics and main controlling factors of the lower part of the 2nd member of Shahejie Formation in Xia 32 block of the Linnan oilfield through observation of core and thin sections and combined with logging data. The results show that the types of reservoir rock are mainly lithic feldspar sandstone and feldspthic lithic sandstone with medium sorting degree, poor roundness and medium compositional maturity and texture maturity. The physical properties of the reservoir are mainly medium-low porosity and ultra-low to low permeability, with a good correlation between porosity and permeability. The pore types include primary intergranular pore, intragranular dissolved pore, intergranular dissolved pore and mold pore. Comprehensive analysis of reservoir characteristics indicates that the reservoir is mainly affected by the base-level cycle, sedimentation, diagenesis and tectonism. The sand body of delta plain branch channel has the best physical properties, followed by the delta front subaqueous distributary channel, and the physical properties of other sedimentary micro-facies reservoirs are poor. Compaction and cementation destroy reservoir physical properties, whereas the dissolution can improve the reservoir physical properties. Besides, the fractures produced by tectonism can also improve reservoir physical properties and play a constructive role in reservoir physical properties.